In the related art, a heat exchanger for automobile made of aluminum alloy is known. This heat exchanger is composed of some parts such as an outer fin, a tube, a header plate, and a side support. Further, in general, the heat exchanger for automobile is manufactured by bonding the parts to each other through a brazing treatment using a fluoride-based flux and performed around 600° C.
In addition, a tube or a header plate composing a heat exchanger is constituted by a brazing sheet.
As the brazing sheet, for example, a brazing sheet in which a brazing material made of Al—Si-based alloy is bonded to one surface of a core material made of aluminum alloy containing Mn, Cu, Si and Fe in the predetermined amounts and a sacrificial material (liner material) made of aluminum alloy with electrochemically lower potential than that of the core material is bonded to the other surface of the core material, is known (for example, refer to Patent Documents 1 and 2).
As the sacrificial material used here, a material having electrochemically lower potential than that of the core material is used, and thereby the material functions as a sacrificial anode material and corrosion of the core material can be prevented.